How do I cut a 9x13 tray into 24 brownies?

A 9 × 13 inch tray is 229 × 330 mm. Twenty-four portions cut most evenly as 4 × 6, giving portions of roughly 57 × 55 mm — almost square. 6 × 4 is the same count but gives long thin fingers instead.

Does it account for the sloped sides of my tin?

No. It works on the flat measurement you give it, so measure across the top of the bake rather than the base of the tin.

What is the offcut figure?

When you fix the portion size, the tray rarely divides into it exactly. The offcut is the strip left along each edge after the last full portion — usually the baker’s share.

Can I cut different sized portions from one tray?

Not here. This works on one repeated portion size, which is the arrangement that keeps portion weights, and therefore prices, consistent.

Free · no account

Cut a traybake into portions that match.

Give it the tray and either the number of portions you need or the portion size you sell. It works out the arrangement, the exact portion dimensions and what is left over, and prints a cutting grid at true size.

Tray width

Tray length

Units

What are you working from?

Portions needed

1 to 200.

Paper

Orientation

Layouts

2 sheets at true size. In the print dialog set scale to 100% / Actual Size — not Fit to Page or Shrink to Fit.

Every sheet carries a 50 mm bar. Measure it before you cut anything: if it is not 50 mm, the printer scaled the page and the guide is wrong.

Trim each sheet on the dashed line, then lap it over the next so the alignment crosses sit on top of each other and tape it.

Worth keeping

18 portions is what a cost per portion gets divided by. Keep it here and it joins whatever you type into the label maker.

Stays in this browser. Nothing is sent anywhere.

Two ways round

A number of portions is the home answer: 18 from a 30 × 20 tray comes out 6 × 3 at 50 × 66.7 mm. A portion size is the business answer, because the size is what the price and the box were set against — so it stays fixed and the yield falls out of it.

Why it suggests other counts

Some numbers do not cut nicely. 17 only factors as 17 × 1, so it is a row of splinters — where a nearby count gives squarer portions, it is offered alongside rather than silently ignored.

Using the grid

Print at 100%, check the 50 mm bar, and lay the sheet beside the tray to mark the edges — then cut between the marks rather than through the paper. Trays past about 19 cm wide need more than one sheet, which the guide handles with an overlap.

Common questions

How do I cut a 9x13 tray into 24 brownies?: A 9 × 13 inch tray is 229 × 330 mm. Twenty-four portions cut most evenly as 4 × 6, giving portions of roughly 57 × 55 mm — almost square. 6 × 4 is the same count but gives long thin fingers instead.
Does it account for the sloped sides of my tin?: No. It works on the flat measurement you give it, so measure across the top of the bake rather than the base of the tin.
What is the offcut figure?: When you fix the portion size, the tray rarely divides into it exactly. The offcut is the strip left along each edge after the last full portion — usually the baker’s share.
Can I cut different sized portions from one tray?: Not here. This works on one repeated portion size, which is the arrangement that keeps portion weights, and therefore prices, consistent.

What BakeCheck does when the baking is a business

This page works out one thing, once. BakeCheck keeps the record behind it — the ingredients, what each product is made of, the allergen declaration, and a label you approved on a date you can point at. All of that is on the free plan.

Make an account — or read what else it does first.

Other free tools

Free label maker
Type ingredients and amounts, get a UK declaration in descending weight order with allergens emphasised.
Cake cutting guide
Printable cutting diagram for a round cake — equal slices at true size, with the angle and edge width worked out.
Cheesecake cutting guide
The same geometry sized for a cheesecake tin, in the sizes and slice counts people actually ask for.